Just found something interesting at ccm website:
Bint's superman app that is preinstalled in some of his firmware versions (24xp, 59xpV2) is now available as an update package.
Superman has functions like
mpkg installer and
linloader so both are not needed with this app installed. And additionally there is a
backup and restore funktion that makes a backup of contacts and messages on TF (don't know about calendar) and can restore after flashing or resetting the phone!
The only little downside is: It's in chinese

but there are only three buttons to tap on in this app (no need to understand chinese):
left button- make backup
center button - restore existing backup
right button - quit
nothing else!!
Loader and mpkg function are the same as with loader and mpkg where you dont tap on the app but tap and hold on the file to install or execute and then choose superman to "open with".
The version I found requires linloader or preinstalled superman (it's made as an update). But I did install it on an empty system folder to make it available for anyone who doesn't have loader or older superman installed. Additionally I changed the name that appears in menu from chinese to english in both versions.
The "loader" version can be installed by copying the "superman" folder in the posted .rar file to the root of TF. Then taping and holding "install.sh" inside this folder and select open with loader. After restarting phone (plug in usb in mass storage mode does work also) superman can be found at "Games". Any other installed app will stay as it was before.
There also is a "delete_origin_superman.sh" to uninstall preinstalled version.
The "system" version is for replacing hidden system folder on TF. Every app, that is installed on TF before has to be reinstalled after this. The same as with mpkg installer
I don't know if it's working with 25p! Maybe someone with 25p is willing to test that?