About Rank9 Labs
A small studio that ships its own products and takes on client work — publishing on Google Play since 2020, with over 200,000 downloads behind us.
How this started
Rank9 Labs began with a problem, not a business plan. After a carrier switch, HD calling quietly stopped working on a phone reporting full signal and giving no reason why. Android knew the answer; nothing surfaced it.
So VoLTE Check was written to read that state and display it. A great many people had the same question — it and 5G Check have since been downloaded over 200,000 times.
What that taught us
Supporting an app across that many devices is a different discipline from building one. You stop trusting documentation and start trusting field reports: manufacturer skins change documented behaviour without saying so, telephony APIs return values that are wrong on particular devices, and the handsets in your analytics look nothing like the ones on your desk.
We have also had apps removed and suspended over the years, and worked through what actually triggered it. That experience is now something clients come to us for.
How we work
We say what we think. If your scope contains work that will not earn its cost, you will hear it before you are invoiced for it.
We give ranges, not false precision. A confident number on an ill-defined scope is a guess wearing a suit.
We hand over cleanly. Source, pipeline and documentation good enough for another team to pick up.
We stay involved. Software needs OS upgrades and policy changes long after launch.
The apps we maintain
Three, all live on Google Play, all still supported.
VoLTE Check reads whether a handset supports Voice over LTE, whether the carrier has provisioned it, and whether IMS has actually registered — the three separate things that must all be true before a VoLTE call can connect, and which nothing on a phone surfaces.
5G Check does the equivalent for 5G, separating what the hardware can do from what the carrier has enabled from what the device is connected to at that moment. Those three get conflated constantly, including by people who should know better.
Tic Tac Toe: Slide XO Duel is the outlier, and deliberately so — a small game built to keep our hand in on the parts of Android that diagnostic tools never touch: animation, state restoration, real-time multiplayer, in-app purchase-free monetisation. Building something outside the usual domain is a reliable way to find out what you have been getting away with.
Why we publish guides
Every one of our apps answers a question, and almost every question has a longer explanation behind it that will not fit in an app.
So the guides exist to carry that explanation: why VoLTE fails in four distinct ways, what IMS registration actually is, why a phone shows 5G and delivers LTE speeds, what the carriers in India and the US and the UK have each deployed. They are written to be useful to someone who never installs anything.
That is a deliberate choice. Documentation written purely to funnel people towards a download reads like it, and the people we most want reading it are exactly the ones who would notice.
What we are not
Not an agency with a bench. There is no pool of developers to allocate, which means we cannot scale onto a large programme at short notice, and we will say so rather than take the work and hire against it.
Not a design studio. We build software that looks considered and behaves properly, but if your project is primarily a brand and visual identity exercise, someone else should lead it.
Not the cheapest option. Work that is handed over cleanly, documented, and still standing in two years costs more upfront than work that is not.
What we do now
We still build our own apps, and take on client work across end-to-end development, Android and iOS, web, custom Android OS and telecom diagnostics.
We are deliberately small — engagements run by people who hold the whole picture. Good for products that need judgement, poor for programmes needing a dozen people in parallel. We will tell you which you have.
Our guides explain the why behind what our apps report. Questions: support@rank9labs.com.