Samsung BlackJack II SGH-i617

So I've had this phone for about 5 days now and cannot get any apps I've downloaded even from the windows mobile website to install on my BJ II. It would install the Telenav that it already had the shortcut for on the phone. But when I follow the directions from the website it doesn't show up where its supposed too. I've tried putting it on compressed and uncompressed with no avail. Any ideas....?? 😕