Note, on an Android phone
- "Memory" typically refers to RAM memory (the memory used temporarily when an application is running, which gets wiped when you turn off your phone), and
- "Storage" to app storage space on the phone and also and the SD card (where apps and their data are permanently stored).
Install App 2 SD or a similar app. This app allows you to move some apps to your phone's SD card (if the app developer has allowed it), which typically has lots more available space than the phone itself. It also alerts you if you install a new app and that app can be moved.
Install DiskUsage and choose to view "App Storage". This will show you how much storage is used by each app on your phone. Each app will use the storage for either:
- apk: This is the actual app. Some apps can be moved from to the SD card to free up space - see above.
- Data: Application data. For some apps, it may be safe to delete this data if it grows too large - see below.
- dalvikCache: This means the app is stored on the SD card, but part of it is also taking up space on your phone's own storage.
Install Uninstaller app. This lists your apps in order of storage used, and also indicates which are on the phone and which are on the SD card (though note that if an app is marked as being on the SD card, it may also be using space on the phone for the “dalvikCache” - see above - in which case removing it from the SD card may also free up space on the phone itself).
The "Data" space for some apps seems to just grow and grow, in particular the official Facebook and Twitter apps. For both these apps, I have on numerous occasions deleted the data for the app with no significant ill-effects that I have noticed (but you do this at your own risk!)
To delete app data, go to Home > Menu -> Settings -> Applications -> Manage applications, find the app, and tap "Clear Data". (Of course, this is not advisable for apps which store data on the phone only, since you will lose all your data!)
Install 1Tap Cleaner or a similar app that allows you to delete data that apps cache on your phone. Clearing this data usually has no bad effects, but any space you free up will gradually get used up again as data is re-cached, so this is only a temporary solution.