A month ago our 3-year-old son started going to preschool. During orientation, we were provided with contact numbers for the teachers. I added those numbers to the address book of my Nexus 6, which was synced to my personal Gmail account.\n\n\nEverything was nice and smooth...until I needed those contacts. A few days ago, I needed to contact the teachers so I pulled out my iPhone 6s Plus, but I couldn't find those numbers. Somehow, the contacts were lost in translation between Android and iOS, even though I was using the same email ID to sync mail and contacts between devices.\n\n\nThis was not the only incident where contacts gave me trouble. I heavily use Google Hangouts to call my family in India and also for international business phone calls. One issue that I continuously face on Hangouts is that it fails to pull contact info from my address book; I have to go to the Contact book, copy the number, and then use it on Hangouts.\n\n\nI was already unhappy with Google showing over 5000 people in my contact list because it pulled in contact details of everyone who circled me on Google+. This makes it hard to find your actual contacts. Being unable to find the teacher\u2019s phone number broke the camel\u2019s back. I started looking for a platform-agnostic contact solution. Something open source was my priority; ownCloud looked good, but it was overkill to run a whole server just to sync contacts.\n\n\nThen I found Addappt. It's not open source, but it is free and available on both iOS and Android.\n\n\nThe way it works is simple. You install the app on your mobile device. It will ask you to provide an email account you want to use to sync your contacts. It will mail you a code for the email. You enter the code in the app and you are all set. All of your contacts are now synced through AddAppt.\n\n\nOk, sounds good, you say, but isn't that what my phone's native contact app does?\n\n\nNot really.\n\n\nIn the native contact app you have to add account details and keep them updated as your contacts change. Addappt takes this management out of the equation. It allows you to manage your contact details in the address book of your friends and colleagues. Of course both you and your contacts need to be using addappt for this to work.\n\n\nAddappt pulls all your profile info from your contact book, and allows you to add additional information such as phone numbers, email address, social network profiles, your physical address and much more.\n\n\nOnce you and your colleague are connected via addappt, whenever you make a change on your profile it will be reflected in his\/her address book. And when a colleague changes his\/her phone number or email address, since you are connected via addappt you will always see the updated information.\n\n\nThis feature alone is quite handy. Recently I changed my email ID for business. I had to send hundreds of emails to PR agencies, friends and contacts in the open source world. Still, whenever I log into my old email ID, which will be defunct soon, I still see people sending emails there. Yes, I did configure an auto-responder and forwarder, but the problem persists.\n\n\nAddappt solves that problem completely. If all of my colleagues and friends were on addappt I would never have to mass email people. The moment I change the contact info they will be updated.\n\n\nAnother advantage is that I gain control over how people contact me. I can choose which email ID or phone number to use for work and which for personal matters. So when people send me an email it will be sent to the email address I want to be used.\n\n\nAnother neat feature for those who travel frequently and often get temporary SIM cards is that you can add the temporary phone number to your profile. This makes it easy for friends and family to get in touch with you without wondering which number to use.\n\n\nI have been using addappt for over a week now and I like everything about it, including the fact that if you engage with a global audience you can also configure your time zone so that contacts know when to call you.\n\n\nOne change that I would like to see in addappt is that I should be able to choose who can see my physical address. I like the idea of having my physical address available for friends and family, but I don't want all of my work contacts to have that information.\n\n\nWhat I liked the most about addappt is that unlike many, or almost all, such services it\u2019s not a walled garden. All contact info is synced with the native contact book on your device. So if you decide to quit addappt today, you won\u2019t lose your contacts.\n\n\nI talked to the CEO and founder of addappt, Mrinal Desai, and he told me that harvesting user data isn't their business goal or model. They store the profile\/contact information of those who join the service as well as who you're connected to, which is how they keep the information synced. But they don't harvest information from your phone's native Contacts app. And if you use the app for messages, they don\u2019t store any message on their servers.\n\n\nIf you are looking for a smarter solution to manage your contact book, addappt is it.