Level 1-8. There is an imprint of an E on the floor of this room. In the code machine enter the shape of an E.
Level 1-9. Press the buttons you see in the following order: 2314. The key will be lowered using the chain. Get the key and escape.
Doors and Rooms level 1-10. Level 1-10, episode 1 room 10 is the most difficult door of chapter 1. The solution is 7239.
For stage 1-10 you might not have seen that some of the keys had a playing card imprint on them. The stages of the different card symbols is what gives you the code to stage 1-10 of Doors and Rooms.
Stage 2-6 of Doors&Rooms. The symbol on the wall tells you to tilt the device. Above the lift door in the room you will see a symbol you can tap on. If you tilt your device after you tap it you will see some numbers. They are very hard to see, and you need to tilt your device quite far. For stage 2-6 imagine you are looking at a very long number and you will see the tilt better.
When you tilt your iPhone, iPad or Android device for level 2-6 of Doors and Rooms you will see the code 8654219634. The code solution to the door is then 5293 because the door already says 8431.
You can find the complete Nerdr walkthrough to Rooms and Doors here. The cheats and solutions here are the answers to just the first chapter only. The full Doors and Rooms walkthrough contains cheats for every stage and every chapter of Doors and Rooms.