These are usefull links, that you and I could use daily.
Google Scholar (find research papers)
Sci-Hub (download research papers)
LibraryGenesis (download textbooks)
SendToKindle (send EPUBs to Kindle)
OldGamesDownload (download old games)
Unsplash (find free high-res images)
Ninite (create PC-Setup package)
TinyEye (check reverse images)
BigJpg (create upscaled image)
VectorMagic (create vector of image)
DownDetector (check service status)
RainyMood (listen to rain sounds)
CanIUse (check browser compatibility)
ThisPersonDoesNotExist (create novel face pictures)
ThisWordDoesNotExist (create novel words n definition)
DPI Analyzer (compare game DPI's)
SteamDB (check steam charts n stats)
HowLongToBeat (check game duration)
TrueAchievements (check game achievements)
HowLongToRead (check book duration)
WhoSampled (check song samples)
MarineTraffic (every ship at the sea right now)
TrueSize (compare geologic sizes)
HDEV (high definition earth viewing system and other stuff about ISS)
ADS-B (stalk planes, includes military)
TheUselessWeb (takes you to random fun sites)
LibraryOfBabel (whatever you thought of.. it exists)
SpokenCorpora (recordings of human conversation)
AllSides (possibly unbiased news)
SpentElonsMoney (can you spent all of Elon Musks money)
ClimateData (temperature graphs for different places)