My fiance is working out of town these days, and it is really easy for me to stay in bed when the alarm on my phone goes off, instead of getting up to work out. I had him record a voicenote for me on my phone, and I use that as the tone that wakes me up.
The message is "Rise and shine, baby. I am so proud of all your hard work." That totally motivates me to get up and keep working hard.