QA or Usability Testing Mobile App (iOS / Android)

Dear freelancer,

We're about to launch an update of a well established crypto app with > 4m downloads, thus we're looking for QA and usability tester for our app in iOs and Android.

Required is that you have somehwat of experience in crypto (e.g. a wallet address), so you can test the portfolio tracker feature of our app.

Please let me know about:
1. your range of services for qa and usability testing
2. your experience of QA mobile app testing
3. historical experience / credentials