If you are using Android for operating system then there are some tools which you can create swap with. For example Swapper2. On smaller phones the convention is to usually put a custom ROM to it, because they are optimized so well you won't have to deal with swap.

t was helpful if your smartphone dont' have so big RAM. For create a swap partitions you need a kernel that support this. To create a swap partition download that app: https://play.google.com/store/apps/details?id=org.azasoft.free.swapper&hl=it

Choose the type (I recommend EXT) and choose space. Check Active swap on boot and reboot your phone and this work!