All the .flow glitches. Proof .flow is way more broken then Yume Nikki.
Using menus in chair: Enter the chair. Hold down shift in the process of entering.
Lock menus to only be able to be used in chair (chair storage): Use instructions in chair.
Speed glitch: Use broom in chair.
Broom speed without broom: Wake up in the chair. Enter back into the dream and activate the invisible chair that will be at the desk.
Walk through walls: Use iron pipe in chair. Activate it right after you leave chair. Entering any of the four nexus locations will cancel the glitch, so doing it at a chair other then the one in Sabitsuki's room would be wise. (Chair storage required for chairs other then the one in Sabitsukis room)
Make Sabitsuki invisible: Get chair storage. Sit in chair and equip arms effect. Enter bed after exiting the chair. Hold down shift, then press X while holding down shift.
Messed up movement glitch: Wake up in chair. Enter back into the dream. Activate invisible chair. Enter bed, hold down shift and press Z then X.
Double speed glitch: Equip instruction in chair while awake. Go to sleep and use arm effect in chair. Wake up. Use instructions in chair a second time. Go to sleep and ignore the invisible chair. Head to Sugar hole and equip the iron pipe on one of the stools. Head to Flesh Walls and use the iron pipe to get into the chair by the whistle effect. Use the broom on the chair. Head back to Sabitsuki's room through rainbow maze. Activate the invisible chair. (https://youtu.be/HAR77pWBFS8
Steal the chair: Do the messed up movement glitch (description above) and after you exit the bed hold up, enter the chair, and hold down shift as you enter the chair. If done correctly you should now be moving with the chair, and the collision should be off.
Softlock .flow: Get chair storage and get caught by a kaibutsu
Get to Dying Girls event very easy: Preform walk through walls at the chair in the flesh walls. Walk across the gap to Dying Girls event.
Believe it or not there is still more, but these are the most noticeable and useful ones.