Ex Deorum is a port of the 1.7 SkyBlock companion mod Ex Nihilo by Erasmus_Crowley. It also borrows ideas from Ex Nihilo Adscensio by unascribed, YUNoMakeGoodMap by LexManos, and Ex Compressum by BlayTheNinth, although Ex Deorum does not use code from any of those mods.
Ex Deorum includes a SkyBlock world type out of the box. All of this mod's recipes exist in data packs. The default recipes only cover items from Vanilla Minecraft, and the sieve drops are generous enough that this mod should be playable without Ex Compressum.
This mod also adds a watering can item, an alternative to bone meal that should alleviate the need for mods like Tree Growing Simulator. There are six tiers, including a wooden watering can, which is given to the player at the start of the world along with a torch (both configurable).
Ex Deorum has JEI support for all of its blocks.
Here's some of what the mod has to offer: