Ios upgrade for ipad mini

Hi,

I have ipad mini, which is having ios version 9.3.5. Since most of the applications doesn't support this version so i am not able to install the new applications. There is no more updates from apple as well to upgrade the ios.

Is there any way, i can download new applications in this ipad? I tried the 'purchase' option in the app store, but its showing only those apps which were earlier installed in the ipad. no option to download any new app.

please help me, now this ipad is kind of useless for me.