Should be able to use this:
Pushbullet - Your devices working better together
Encrypted by default but can add second layer by enabling end to end encryption with a password of your choosing via settings in the app. I use it on my Windows and Android. Don't know how it works on iPhone. You can push text, images, etc to each device. On Android you can receive texts and other notifications and see them on your PC. Pushbullet allows you to reply to text message without your phone but the free version only allows 100 a month. Stupid yes but it's enough for me since I hate phones.
Seems you must have Google account or Facebook to sign in. I use Google account. Apart from that, I'm sure there are some others including just sending the URL to your own email, etc.