HOW TO INSTALL 2 VERSIONS OF APPLICATION ON ONE PHONE

1-Install a version of desired application
2-Using some file explorer, go to !:\system\apps\ and find the folder of the application you've just installed.
3-Rename this folder to anything other than its current name
4-After a few seconds, the application will disappear from phone's menu.You can create a folder somewhere in your MMC to keep applications such like these, if you are going to do this trick with several apps
5-Install another version of the same application in your phone
6-The version that has just been installed will appear in phone's menu and work normally.
7-To use the other version that had its folder renamed, use some file explorer, like Fexplorer, System Explorer, or ExplorerSP*, go to that folder you had renamed before, and open the .app file.The application should open normally, but without its icon.If it doesn't open after you select the .app file, this app is not compatible with this trick.For example, you can use this trick to have Netfront3.2 and 3.3 in your phone.Note that Netfront3.3 should be installed first, cause it works from any place, even with its folder renamed, and Netfront 3.2 only works from !:\system\apps\ .However, both netfronts will use NETFRONT3 folder located at !:\system\apps\, for example, to hold the cache


Notes:
-Keep in mind many applications doesn't work properly when they're not located at !:\system\apps\ or after having their folder name changed.A few doesn't open, a few close when you try to use some functions, a few require different settings file, but a few work perfectly
Alternatively, even if a application doesn't work in such conditions, you can let it at !:\system\apps\ with its folder name changed.Whenever you want to use this application, just rename the folder of the current version (that should be installed and appearing in phone's menu) to disable it, and rename the folder of the app you want to activate to its original name(the same name than .app file).The application should appear in your phone's menuSome applications that work from any place:

Netfront 3.3
AC ping v1.13
S60zip v1.02
Camera Magica
Instant SIS v2.1
Sonic Boy 1.0
Vnes 1.60
Vsun 1.10

Even if you're not going to install two or more versions of a same application in your phone, you can still use this technique to avoid having your phone's menu with lots of applications.In a phone that has more applications installed, when you press Menu key for the first time after the phone is turned on, it will take more time until Menu appears at the screen.You may have to wait half of a minute or more, if your phone has too many applications installed*Don't use SmartFileman, cause it can't open some applications properly.