Todo Math offers users the ability to sync profiles between devices, which includes syncing between iOS and Android. This means that you can pick up and play your account on multiple devices.
In order to sync between devices, you'll need to be connected to WiFi, and you'll need to enable the sync feature:
1) Open Todo Math and tap on a profile name above the big "GO" button.
2) On the "Who Will Play Todo Math?" page, tap the gear icon in the upper right corner (next to the little plus sign).
3) Tap the profile that you want to sync.
4) On the "Your Profile" screen, you will see a title that says "Sync" located to the right of your User Name. Under the "Sync" title, there is a check box. If you want to start syncing, tap that box.
5) If you have successfully, synced the profile, the box and the word "Sync" will disappear and be replaced by text that confirms that your profile is being synced.
6) Now, if you sign into Todo Math on another device using the same email address, your profile should sync, meaning that you can access your profile and continue progress from any device that is synced. This also works for syncing from an iOS to an Android device and vice versa.