Credits

MiRO92 for uYou.
Galactic-Dev and Luewii for iSponsorBlock.
HASHBANG Productions for Alderis Color Picker - a dependency of iSponsorBlock.
PoomSmart - the developer of many tweaks used by uYouPlus, include: YouRememberCaption, YTClassicVideoQuality, YTNoCheckLocalNetwork, YTSystemAppearance, YTUHD and YouPiP.
level3tjg - for YTNoHoverCards.
Al4ise for Azule, a tool used to inject jailbreak tweaks into jailed iOS apps.
theos team for theos & theos-jailed.

Features

uYou: uYou has a ton of features that I can't list them all. Visit his here for more info!
iSponsorBlock: Skips annoying sponsor ads inside videos. iSponsorBlock is based on SponsorBlock engine. Basically, this is the iOS version of the SponsorBlock extension.
YouRememberCaption: make YouTube remember your video caption setting (if not already).
YTClassicVideoQuality: since YouTube v16.xx, you need one more step to change the video quality. YTClassicVideoQuality brings back the old video quality selector, which is a lot better than the new one.
YTNoCheckLocalNetwork: block the Local Network permission popup.
YTNoHoverCards: offer an option to enable/disable the annoying suggested videos show up at the end of the videos.
YTSystemAppearance: sync the YouTube theme (dark/light) with the system theme.
YTUHD: unlock VP9 codec and in effect, enables video quality of 2K and 4K. You can enable/disable YTUHD in YouTube Settings => Video quality preferences.
YouPiP: enable YouTube's native PiP. More options are in YouTube Settings => General.

uYou: all known-issues of uYou are listed here. Make sure you take a look at it before reporting any bugs! Also, keep in mind that uYou+ is a modified version of uYou, DO NOT bother MiRO92 with problems unrelated to uYou!!!
iSponsorBlock: the modified time doesn't show up in the seek bar.
YTUHD: Stuttering on 4K videos (sometimes).
YouPiP (iOS 14.0 - 14.4.2): due to Apple's fault, you may encounter the speedup-bug as described here. The bug also happens when you try to play multi-sources of sound at the same time. Enable Legacy PiP is a workaround. Note that Legacy PiP removes UHD quality and breaks the default video quality feature of uYou. Use it at your own risk.
Not a bug:

The app won't be able to receive push notifications if you use a free developer account.
appdb PRO users: follow this guide to fix uYou download not working.
It is impossible to fix deep-link (a.k.a Open in the YouTube app). However, you can use this Shortcuts as a workaround (tested on iOS 14). Credit: RandomAccessMemories#5025

uYouPlus (or you can call it uYou+) requires iOS & iPadOS 13.0 or later. The latest version of uYouPlus can be found in the Release tab.
For AltStore user: Open in AltStore. (Note: It will take a while to install because AltStore need to download the IPA).
Version info: (last update: Oct 28)