Link2SD

Link2SD is an application that makes it easy for Android users with root privileges on their phone to move applications to the SD card.

The idea behind is same with apps2sd scripts, linking applications to SD card ext2 partition but differs in two ways.

One, instead of linking /data/app folder (that means moving all applications), you can select applications that you want to move.
Two, its an application which means has a user interface. You can manage your applications, create or remove links with just one click.

Features:
- Creates and removes link for application you select
- Lists applications, shows they are linked or not
- Sorts and filters applications
- Displays available space information of phone, SD card and SD card ext2 partition.
- Repairs missing Market applications

What you need:
- root permission.
- ext2 partition on your SD card. 2 partitions set up, first FAT32 and second ext2, both are primary.
- Thats all. Just install Link2SD, it will do all necessary. No need to copy files or run scripts.

How it works:
Link2SD mounts ext2 partition of your SD card as /data/sdext2 and makes OS mounts it at boot time.

When you select an application and press Create Link button it moves apk file to SD ext2 partition and creates a symbolic link in original directory (/data/app).

Note: After this step, application icon disappears from the phone on Android 1.6 and 2.1, but after reboot you can see and run without problems. On 2.2+ this is not the case.

Can I remove the link and put application back to phone?
Yes, just click on application which is linked and press Remove Link button. Link2SD removes symbolic link and moves apk file to orginal directory.

What happens if I uninstall a linked application?
If you uninstall a linked application it will be uninstalled from the system but apk file remains in /data/sdext2 directory, you need to delete it manually.
Or remove the link before uninstalling.

What happens if I update a linked application?
If you update a linked application new apk file will be placed in the internal memory (/data/app directory), old apk remains in ext2 (/data/sdext2 directory).
Therefore application apk file is not linked anymore after update and you need to create link again. After linking, new apk file will be moved to ext2 (replaces old one).

Android Market and Link2SD
Android Market doesnt see applications that have been link to SD card. Because a background process marks them as UNINSTALLED when the link created.
To repair their state use Market Fix menu.
This will synchronize Android Market database with installed applications and missing market apps will be repaired.
Before starting, make sure market is not running and youre not downloading anything from the market.

NOTE: If some apps are still missing from My apps afterwards, just install any app from the market and they will show up.

Some points
- If you applied App2sd, please uninstall App2sd and revert to original. Otherwise you cannot create link with Link2SD. Link2SD detects this and warns you at startup.
- Link2SD detects applications which are already moved to SD card on Android 2.2+ natively and disables create link for them.
- System applications should not be linked to SD card. Link2SD does not allow these applications to be linked.
- When you connect your phone to PC as mass storage, Android unmounts FAT partition but ext2 mount remains. Therefore linked applications are not affected and can be run without problems.
- Link2SD does not move data and dalvik-cache, it only moves the apk file. This is what Android 2.2+ does. APKs are actually on the card; the dex files, private data directories, and native shared libraries remain in internal storage.

DISCLAIMER: It is made available for use at your own risk with no warranty of any kind.