What is the app cache? Is it safe to clear them?
The cache storage is used for applications to cache some data. When the device is low on internal storage space, Android may delete these cache files to recover space; hence it is safe for you to clear the cached files manually.
The "Clear all cache" command does not clear all cached files
First of all, not all Android versions clear cached files which create on the SD card. You can show the external cache size by checking the "Count app used SD size" option, and manually clean them by tapping the app item from the Cache cleaner window. If the primary external storage is emulated (it means that the storage is allocated using a portion of the internal storage), Android 4.2+ will also delete the cache files of primary external storage when clearing all cache.
The another problem is starting Android 4.2, Android prevents 3rd party apps to remove some cached files, so you may see few KB cache size left after you clear all cached files. You can check "Ignore apps with tiny cache" option to only count app that cache size over 100K bytes.
What is the app data? Is it safe to clear them?
The app data includes all app created files, settings, accounts, databases and so on. All of this application's data will be deleted permanently if you clear the app data. When your device is low on internal storage space, clearing the app data is better than uninstall it. Not all devices provide the "Clear Data" button, please consult your phone manufacture if you do not find this option.
What are the search and browser navigation history records?
Some applications, like Gmail/Google Play, will provide a search suggestions function for users. To implement this function, these apps will save the recent queries, or page/items viewed, etc. in the local storage. In addition, Browser app will log the visited URLs in a database. You can clear them for getting more available space and protecting your privacy. Please note that, not all apps (Maps, Sky Map, Twitter) open the permissions for 3rd apps to clear the history records. You have to clear the history from the app provided UI.
What are the default apps? Do I need to clear them?
When you want to perform an action on the phone and there are multiple apps can complete that action, system will pop up a dialog allowing you to pick an app to use and optionally marking that as preferred. If you have selected an app as default for an action. This app is the default app for that action and system won't show a dialog asking you to pick an app any more.
You can list all default apps and reset them via Defaults Cleaner provided functions.
The Frequently Called log won't be cleared on Android 4.0.x (ICS) devices.
Android 4.0.x (ICS) does not enable 3rd apps to clear this log.
Google fixed this problem in Android 4.1 (Jelly bean).
On ICS devices, you can manually clear the frequently contacted log by going to:
Launcher > MENU > Settings > Applications > Manage Applications > All >
Contacts Storage > tap the "Clear data" button
WARNING:: This will delete not only the frequently called list, but also the
entire call history log and contacts. As long as your contacts are backed up with
Google, then they will automatically return within a minute or so when your phone
re-syncs contacts with Google.
It takes time to list apps on startup. Can you improve it?
It can be improved by saving apps information. We don't want to take this approach as it needs the phone internal storage space for saving the information. We keep improving the loading speed by using another approach.
Do I need to ROOT my phone to use this app?
No, you don't. This app supports either non-root or root Android v2.2+ devices.