I know exactly how old it is. I'm asking for help to backport it, not for advice to buy a new device.
If it was on fdroid in the past, it will be on fdroid's archive repo. I don't know how to search for it from the page, but fdroidcl (with fdroid's archive repo enabled) can find it. If my discovery is enough for you, just install/enable fdroid's archive and install it from the fdroid client. Code: $ fdroidcl search essential launcher de.clemensbartz.android.launcher Essential Launcher - 2.2 (20) de.nodomain.tobihille.seniorlauncher Senior Launcher - 1.7 (7000) Launcher reduced to the essential, intended for elderly people
Fdroid only provides ready apk files, not the source you want to patch, so it is practically useless. The github repos from the ones who forked the original do contain the source.