The browser I used every day shut down, so I built my own

Ask anyone how to pick your first indie product and you will hear the same word: research. Find out what people need, study the competition, look for a gap you can win. That is what the books say.

The Mac app I sell today had no market research behind it. None. The software I used every day disappeared, so I built the replacement myself. That is the whole origin story.

This is the first post in a series about taking one app from nothing to something people can buy. I want to start with why it got built at all.

A lifetime license, for $44.10

On April 2, 2024 I bought a browser called Sidekick on AppSumo. The price was $44.10.

AppSumo sells lifetime deals, and I have used it for years. I do not want to stack up monthly subscriptions, so when something can be bought once and owned, I buy it once and own it.

Sidekick belonged to a category people call the app browser. Gmail, Calendar, Todoist, Slack: the web apps you open every day get pinned into a sidebar and live there permanently, in their own space, separate from ordinary tabs.

It also had workspaces. A workspace held a set of apps and a set of logged-in accounts, and you could switch the whole thing at once: work, personal, one per client.

I have several Gmail accounts. One runs @SOHO, one handles students from my course, one is mine. Keeping all of them open in a single browser and moving between them turned out to matter far more than I expected. Not switching is not a small convenience. It changes the quality of the work.

The ending was decided before I bought it

In the summer of 2025 I learned Sidekick was shutting down.

I had bought it outright, so a shutdown did not sit right with me, and on August 1, 2025 I asked AppSumo for a refund. The answer was something.

Sidekick Browser originally announced their decision to sunset the tool back in 2024.

Sidekick had already decided to shut down, and said so publicly, in 2024. I bought it on April 2, 2024.

So I had bought a lifetime license to a product whose makers had already decided to fold it.

AppSumo refunded the full amount in credit, and I think they handled it honestly. But money was all that came back. The working environment I had spent sixteen months building into my day did not.

The $44.10 was not the loss. Losing a tool I used eight hours a day was.

An acquisition, and a successor that is not one

The way Sidekick ended is not somebody else's problem if you build software alone.

Sidekick was a six-year-old startup, and Perplexity acquired it. The team moved on to build Comet, Perplexity's AI browser. The official shutdown date was August 3, 2025. Open meetsidekick.com today and it redirects to comet.perplexity.ai.

As a company, that is a success. They got acquired, and the team is building the next thing. Nobody did anything wrong.

But I installed Comet and used it, and what became clear is that it is not Sidekick's successor. Comet is aiming at a browser with an AI assistant built in. What I wanted was a design where several accounts stay open and you never switch. Those are different goals, and the idea of a workspace is different underneath.

Users rarely carry over in an acquisition. What carries over is the team and the technology, not the daily environment of the people who lived in the product.

I tried the alternatives, all of them

Then came the search for a replacement. These are only the ones still installed on my Mac:

Comet, from Perplexity, built by the Sidekick team
Wavebox, subscription, the serious contender among app browsers
Rambox, a dedicated tool for collecting web apps into one window
Stack, which shows several services side by side
WebCatalog, which separates accounts with its Spaces feature
Arc, Vivaldi, Brave and Opera, browsers with tab organization or workspaces

There were more that I installed and deleted.

Not one of them fit.

Some came close. Wavebox is genuinely near it on features. But it is a subscription, and three years of it runs past $500. The reason I chose Sidekick in the first place was that it was a one-time purchase. Solving the same problem again, monthly, felt like going backwards.

This is where most people compromise, and often compromising is the right call.

I did not compromise. I did something more embarrassing instead.

I kept a dead product alive

Honestly: I went on using Sidekick after it shut down, for a while. The servers were gone, but most of it still worked offline.

Three things stopped working, all in the same place. Renaming a workspace, adding one, deleting one. Sidekick's workspace operations had been built assuming they could sync with a server.

So I went around the restriction by writing directly into the extension's internal chrome.storage.local over the Chrome DevTools Protocol. The full procedure is in a separate post.

I went that far to keep using it. Which is to say I spent my time keeping a dead product breathing.

I knew it while I was doing it. Nothing I piled up there would ever belong to me.

If I was going to spend the effort anyway, it should go somewhere that became mine.

July 17, 2026

The first commit in my repository reads:

chore: initial commit - Sidekick successor browser, MV3 extension spike verified

The date is July 17, 2026.

The commit message says the spike was verified because I did not simply start building. There was exactly one technical mountain, and it was clear: could Chromium extensions really run on top of Electron?

Most existing app-collection tools just embed web pages in frames and line them up. Extensions do not work in that arrangement. An environment with no password manager, no ad blocker and no translation was never going to be usable for me.

So I tested that one thing first, confirmed it worked, and only then cut the initial commit.

From there, about 211 commits in seven weeks. Apple Developer ID signing, notarization, Touch ID, and the infrastructure to ship automatic updates. As of September 2026 it is available at spacedeck.app.

I named it SpaceDeck. Space for workspace, deck for holding them together.

Your own problem is the best primary source there is

Here is the part you can use.

Plenty of people start the hunt for an idea with market research. I used to teach it that way myself.

What I learned by actually doing the work is that a problem you have yourself carries information that research cannot buy:

You know where it hurts in your body, not in your head
You can tell the essential feature from the decorative one without hesitating
You judge competitors by using them for a year, not by reading reviews
You are your own first user, every day, while you are still building

I used Sidekick for sixteen months and installed more than ten alternatives. As research budgets go that is substantial, except I paid in my own working life rather than money. That information is not for sale anywhere.

So when it came time to decide what SpaceDeck should do, I did not have to ask anyone. I worked down the list of things that had annoyed me every day.

Which means that most of the time, having no idea what to build may just mean nobody wrote the annoyances down. Keep the small daily "this is tedious" instead of dismissing it, and the list becomes the notebook.

There is a trap in this

It would be a nice story to end there.

But your own problem and other people's problems are not the same thing at all, and I found that out after I shipped.

I finished it, signed it, got it notarized, built the site, wired up payments, and put it into the world.

Here is what happened. Two to six visitors a day. One download, total.

The building is essentially done and nobody knows it exists.

Next time I am publishing all of those numbers exactly as they are. Where the visitors come from, what happened the day after a listing site picked it up, and which numbers in the analytics tools are lying.

Shipping is not the end, and I am going to write that part without flinching.