SLYNUMBER

Review by eFreeware

If you hand out your phone number often enough, you eventually want a second one. Freelancers who publish a contact number on a website, job applicants, sellers meeting strangers from classified listings, and people dating online all run into the same problem: the number they hand out is the one tied to their real identity. SLYNUMBER from MobileSphere is built for exactly that situation, offering a separate line for calls and texts while the number you actually live with stays out of circulation.

The app has been downloaded more than 500,000 times and holds a 4.2 average from 1,463 ratings, which suggests a settled product rather than a new experiment. It arrived in September 2022 and was last updated in September 2026. The download is free, there are no ads, and the service itself runs on paid subscriptions and credit purchases.

One line for the public, one for you

The idea is straightforward. You install the app, choose a number from what is available, and from that point you can place and receive calls and send and receive texts through it. The developer's pitch is that this second line behaves like your main one, so the people you deal with do not have to learn a new way of reaching you.

Where SLYNUMBER tries to stand apart is in the type of number it issues. The developer says it supplies real mobile numbers rather than VoIP lines, and argues this matters because plenty of services and apps reject VoIP numbers when you try to register with them. That is the claim the whole product rests on, and it is the reason the app is positioned against both cheap virtual-number tools and a conventional carrier plan with a SIM card and a monthly bill.

Privacy is the other half of the pitch. The developer describes the app as a way to share a contact number with clients, acquaintances or people you have just met without exposing the line that identifies you.

Calling, texting and the controls around them

Day-to-day use covers the basics you would expect from a phone line: incoming and outgoing calls, SMS, and a set of controls for managing them. The developer lists spam blocking, call muting, do-not-disturb mode, caller name and ID settings, and call forwarding among the features. Number porting is also mentioned, which matters if you already have a second number elsewhere and would rather not start over.

Toll-free calls cost nothing, and international calling is supported at rates that vary by destination country. That combination makes the app more useful for someone who regularly calls abroad than a plain second-line tool would be, though the per-country rates are something you would want to check before relying on it.

There is also SlyAI, which runs on ChatGPT-4, and an eSIM feature for activating cellular data while traveling. The eSIM option is the more consequential of the two for anyone who spends time outside their home country, since it addresses data rather than just voice.

Where the subscription model bites

SLYNUMBER is not free to use beyond the download. Two plans are offered. The three-month base plan costs $4.99 per month, billed as $14.99 every three months. The annual plan works out to $4.18 per month, billed once a year at $49.99. Each plan comes with 100 outbound credits a month, and incoming calls and texts are unlimited.

Those credits are the part worth understanding before you commit. One credit covers a one-minute outgoing call or a single outgoing text, so 100 credits is a modest allowance for anyone who makes the second number their main way of reaching people. Extra credits cost $10 for 1,000, and international rates depend on the country being called. Subscriptions renew automatically unless canceled, and can be managed inside the app.

The developer is direct about one thing that catches people out: there is no free trial. Outgoing calls and texts require credits, so the cost of trying the service is the cost of a plan. That is a reasonable arrangement for a paid utility, but it means you should be confident about the use case before subscribing rather than treating it as something to sample.

What you need before you start

Setup is described as short: download the app, pick a number, and begin.

The requirement that shapes everything else is the subscription plus outbound credits. A second number that receives unlimited calls and texts but charges for what you send is a particular shape of product, and it fits someone whose second line is mostly inbound: a business listing, a support contact, a number on a marketplace profile. If your pattern is the reverse, with most of the traffic going out, the credit allowance becomes the thing you watch.

The app collects no personal information beyond what is needed to process payments.

The people this fits

The clearest fit is anyone who needs a contact number that is not their own. A job seeker putting a number on applications, a small business owner publishing a line for inquiries, someone renting out a room and fielding messages from strangers, or a person dating online who would rather not hand over the number their bank knows them by. The app's stated uses line up with those situations, along with keeping personal and transactional contact details separate.

Travelers are another group the developer has in mind, and the eSIM feature speaks to that directly by covering cellular data abroad. Frequent international callers also get something here, provided they check the rates for the countries they call most.

What ties these users together is that they want a working phone line, not a messaging account. The developer's emphasis on real mobile numbers rather than VoIP is aimed at people who have already run into a service that refused their virtual number, and that is the audience most likely to find the subscription worth paying.

A paid second line that behaves like a real one

SLYNUMBER is a subscription service, not a free utility, and it should be judged that way. For $4.18 to $4.99 per month you get a second mobile number with unlimited incoming calls and texts, 100 outbound credits, spam blocking, do-not-disturb, call forwarding, porting, international calling and an eSIM option for data abroad.

The costs to weigh are the monthly outbound allowance and the lack of a trial. Someone who mostly receives calls on the second line will find the credit system generous enough; someone who sends a lot of texts or makes long outgoing calls will be buying extra credits at $10 per 1,000. Either way, the first payment is the test, so it pays to be sure the use case is real before signing up.

If you need a number to hand out that is not the one you live with, and you want it to work anywhere a normal mobile number works, this is a well-established option with a fair amount of user history behind it. If your second line would be mostly outbound, budget for the credits on top of the plan.

What's new in version 12.6

Bug fixes