Tokii helps you stay in touch on a personal level with your significant other, and specializes in facilitating communication during every stage of the relationship. It's free and private, and can even be fun with features like the mood meter, games and interactive play, and of course you can send messages back and forth. As stated above Tokii is free and you can grab the download from the Play Store link here.
Loving is a social app for couples. Stay in touch with that special someone in your life with messages, voice messages, pictures, privately, and for free. Other features like private chat records all your messages and saves them for you two only, as well as the private album with an encryption for your photos. A couple of other cool and unique features are the send distance function which lets you alert them to your location, and the Alarm feature which lets you wake your significant other any where, any time with just one tap. Loving is free and you can grab the download from the Play Store link here.
My Darling is another social app for couples. Register your significant other and store intimate and important details like birthdays and anniversary's,(although you probably shouldn't rely on the app to remember those two things)and keep the data handy through the homescreen widget which updates periodically. Store personal information for the two of you in the love journal, enter and check important dates in the love calendar, and the app even has support for Android Wear. Any couples out there with matching Moto 360's? My Darling is free and you can grab the download from the Play Store link here.
Twyxt is a private and secure messaging app for couples. Foster better communication by having your own separate and private app to stay in touch. Keep in sync with all the things you and your significant other hold important with shared lists for things like movie dates, grocery lists, dates for outings and anything else you want to share. One of the coolest features is the unique KISS feature which alerts you when your significant other is sharing the same moment in the app with you by illuminating the Twyxt icon. When this happens you two can touch and hold on the icon to share a kiss even if you're not together. Share messages and photos, and save moments to look back on. Twyxt is free and you can grab the download from the Play Store link here.
Couplete makes you and your special someone feel complete with a special place to share private moments. It features fast private and secure messaging between just the two of you. share messages and photos and express moods with emoticons. Use the Wishlist feature to share real-time syncing to-do lists so you can stay up to date with everything that you want to do with your partner. You can even send love letters with stickers and keep all the best moments using the Story feature. Couplete is free and you can grab the download from the Play Store link here.
LokLok: Connected Lockscreen
LokLok is a great way for you and your significant other to send fun messages back and forth. Make sure your message is the first thing they see by sending it using LokLok, and when they receive it they'll be able to view it the moment they wake their screen. Leaving little notes is just part of it, you can leave little drawings and sketches too. It's a great way to keep in touch with quick little messages and just generally letting your partner know how you feel. LokLok: Connected Lock Screen is free and you can grab the download from the Play Store link here.
Wunderlist is great for sharing ideas, to-do lists, grocery lists and anything else you and your partner find important with each other. Real-time sync instantly updates your lists no matter where you are, and you can share them even simpler than before. Once you have a to-do list setup, you can communicate with the people you have shared it with by leaving comments. One of the best features is that you can set reminders for your lists so you never forget important deadlines. Wunderlist is free and you can grab the download from the Play Store link here.
Avocado - Chat For Couples
Avocado is a secure chat app for couples. Send and share private messages, photos and moments. All your messages, pictures, and doodles are kept in one place, safe and secure just for you and your partner. Get notified if you partner's battery is dying, document and save your dating moments and adventures so you can look back at them later. You can use Avocado to share calendars and lists, and even send hugs and kisses. You can even access all the pictures, messages, lists, dates, and moments through the web. You know, in case of that dead battery. Avocado is free and you can grab the download from the Play Store link here.
Couple is one of the best apps available for sharing all the best moments with your partner. Send private messages and photos over a secure interface. Keep a private timeline so you and your partner can build a shared history and remember all the best memories. Broadcast your location in real-time so you two can meet up any time if you're not already together. You can sketch together together in real-time and draw or play games simultaneously. There's even a cool feature called the Thumb Kiss, which lets you and your partner touch the same spot on the screen at the same time to make the screen vibrate for a feeling of closeness when you're apart. There's a web app too, so you can chat and use the features of Couple from your computer. Couple is free and you can grab the download from the Play Store link here.
Between is the leading app for couples where you can share all the special moments between you and your significant other. Chat privately, fast and securely, with one on one messaging that includes fun, cute stickers, stamps to convey your moods and help you communicate better with more than just words. Share and enjoy the Moments feature, which is private photo album that you can your partner can add pictures too. The app is synced between both you and your partner, so photos either of you add are viewable by both of you in the Moments albums. Keep the Between app safe with secure lock, customize the background with you and your partners favorite photo. Find special deals and resources meant just for relationships in the Event Box. There's even weather updates to show each partner visually the weather that each person is experiencing while you're apart. Of course there's also a shared calendar so you and your partner can sync your schedules and dates. Between is free, and you can grab the download from the Play Store link here.