How can I WBTB without bothering my light sleeping partner?

Any tips for alarm apps or ways to do this and still keep a happy home welcome here.

Do you ever wake up at night? For example to use the restroom? If so, and if it's already at least 4 hrs after beginning of sleep, you can use it to stay up for WBTB. If it's still too early, drink some water that will wake you up in 1-2 hrs for restroom again.

Or a vibrating alarm under your pillow.

Or you can train your subcon to do it for you. Write down on a 3x5 index with a black sharpie "I wake up at _____ every night". Then, highlight the statement in bright yellow. Put the card in your pocket and read it often during the day. When you read it, visualize yourself waking up at that time, opening your eyes, sitting up in bed, etc. Capture how it feels knowing your subconscious is trained now to wake you up every night at that time. Capturing the feeling and emotion when you see yourself waking up is extremely important. Every time you look at the yellow highlighted statement on the index card, remember to capture that emotion and associate it with the visual of awakening. It won't be long before your nightly awakening will manifest just as you programmed it. Just give it a few days. Note: you can use this technique for just about anything you desire to implement/change in your life.

Alarm Clock Xtreme is a good option for Andriod, plus it's free. It allows you to set alarms that will only vibrate (so only you are awoken) and that will auto-snooze (so you don't have to move or open your eyes) for a programmable amount of time (say 90 minutes). It's the perfect alarm for the Rhythmic Napping method, which is basically WBTB but repeated several times throughout a single night/morning. It sort of "hacks" your sleep cycles by repeatedly interrupting them, so that your body falls back asleep very quickly, allowing you to maintain lucidity much easier (less wait time). It's sort of like when you hit the snooze button on your alarm over and over, and manage to fall asleep (and even have dreams) in the brief 5-minute window between the alarm going off. Same sort of thing, but you try to stay lucid the whole time.

You can train yourself pretty easily to wake up without an alarm. Set intention before sleep to wake up five minutes before you get up for your day in the morning, fall asleep thinking about it. Most people see results the first morning but if you don't give it three nights of effort. Once you can consistently wake up before your alarm just intend to wake up for your WBTB, whenever that is. Your body's internal clock is a pretty fine tuned thing, you should be able to do this with little effort.