Hi! I see you're having trouble with the Keiser M Series app getting stuck at the login screen on your Android device. Let's work through this together.

First, can I confirm if you're able to open the app fully, or does it freeze immediately at login? Also, have you tried any steps so far, like restarting your device or checking your internet connection?

To start, here are some straightforward steps that often help:

1. Check Internet Connection: Make sure your Android device has a stable internet connection, preferably Wi-Fi or strong mobile data.

2. Restart the App: Close the app completely and reopen it. On Android, use the recent apps menu to swipe the app away.

3. Clear App Cache and Data:
- Go to your device's Settings.
- Tap on "Apps" or "Applications."
- Find and select the Keiser M Series app.
- Tap "Storage."
- Tap "Clear Cache" first, then "Clear Data." (Note: Clearing data may require you to enter login information again.)

4. Update the App: Check the Google Play Store to ensure the Keiser M Series app is up to date. Sometimes login problems are fixed in newer versions.

5. Restart Your Device: A simple reboot of your Android phone or tablet can resolve many app issues.

If these steps don’t work, the problem might be related to server or account issues, or possibly a firmware update needed for the M Series hardware if you're connecting physical devices.

I also saw that some users had success with running the "Keiser M Series Converter Updater" tool for firmware updates, but since you’re stuck at login, we should focus on app or account access first.

Could you let me know which of these steps you have tried? Also, if there’s any error message when it gets stuck, that info will be very helpful for me to guide you better.