Pick your platform. You'll redeem your licence key the first time you open it.
Platinum Workbench is a desktop app for macOS and Windows — it won't run on a phone. Copy the link below and open it on your computer.
Windows may still show a SmartScreen prompt. This installer is signed — check that Publisher reads THINK PLATINUM LTD, then click More info and Run anyway. If it names anyone else, or says Unknown publisher, don't run it — email info@thinkplatinum.com.