What do you mean by Maemo app? All applications on Maemo devices are technically Maemo apps. Do you mean older Maemo applications?

Theoretically you can install them but due to their design they may have the following problems..

a) dependencies no longer exist (they won't work)
b) they will install to rootfs, which you have very limited space causing a memory issue down the line (because they're not optified since they were meant for older tablets that had a different partition file system).