2 apps that don't open...

hi there! i have an iphone 3gs running 4.0.1 JB...
i also have here a big problem, hopping that you guys could give me a hand...

i can't open in my iphone these programs: Download Meter and QuickMark QR Code Reader...

Download Meter, when i hit the app button on main screen, the displays goes all black for about 5 seconds and then it turns to main screen again... in other words, the app isn't opened...
this is a nice app for those like me who use 3g for access net in iphone, because we can define all the things, and control the traffic...

QuickMark, when i hit the button from the main screen, it appears the apresentation image from the program, but then it disapears... and i'm back to the main menu...

both these app i got it from apptrackr.org, and it is supposed to be the last versions and iOS4 compatible... so i don't understant why these 2 app don't opened...

so people, does anybody could give me some help to solve this problem, please??

thanks!!!

 

but where should i go to get some help in this?

in this forum i have read about cydia, about jailbreak, this isn't part of a jailbreak too? (i supposed...)

but if moderators see that i'm against the rules, please advice...