Comparison

Second Line Calling/Texting vs SkyDuo

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Second Line Calling/Texting

Add a second phone number to your device for private texting and calling. Protect your personal number from spam and unwanted calls when dating, selling online, or for any project. Easily manage multiple numbers and contacts within the app.

Highlights
  • Add a second phone number
  • Keep personal number private
  • Unlimited texts and calls (premium)
  • Create multiple numbers
  • Separate contacts
  • Burn temporary numbers
  • Mask caller ID
Features
Read full description

Flexible Numbers - Add another phone number on your existing device Keep your personal phone number private Instead of giving out your personal number, create a new one and never worry about privacy or receiving spam calls. Use it for dating, online ads or anything else! Get a number in seconds Getting started is simple! Just download the app and start texting or calling right away Unlimited Texts & Calls With the premium plan, get unlimited texting and calling in the US and Canada Create multiple numbers Stay in control by creating multiple numbers on the same device Unlimited calling, texting and picture messaging Make calls and send and receive messages right from the app, using any of your numbers. Easily switch between your numbers at any time Separate contacts Manage your contacts separately from your phone's contacts Protect your privacy Protect your app with a passcode, Touch ID or Face ID Temporary numbers When you are done with a phone number, simply burn it Mask your caller ID with a new, private, flexible and reliable phone number Flexible Numbers Phone is a second phone number for everyday situations such as dating, relationships and more The best number changer app for private texting and calling! It's just like any other phone number but it protects your carrier number and safeguards your identity. A layer of security between you and the ones you are texting and calling. Flexible Numbers Phone is the perfect temporary number for: • buying things online (like craigslist, ebay, etc) • online dating (stay safe!) • applying for jobs • hosting airbnbs • any other kind of project! Avoid giving out your real carrier number to strangers and give out your Flexible Numbers Phone number instead! To get started download the app and get your new number now! Premium Number Plan: - We offer a monthly premium subscription plan that offers unlimited calls, texts and MMS messages within North America - We also offer a monthly basic subscription plan that offers a phone number for texting and calling within North America - Payment will be charged to iTunes Account at confirmation of purchase and at the end of each month - Your subscription automatically renews unless auto-renewal is turned off at least 24 hours before the end of the current monthly subscription - You can manage your subscription and switch off the auto-renewal by going to your account settings after purchase - You cannot cancel the current subscription during the active subscription period - Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable - Privacy Policy: https://flexiblenumbers.com/privacy/ - Terms: https://flexiblenumbers.com/terms/ You may not use the service for sending fake texts, prank texts, spoof texts or for anonymous texting or anonymous calling. The recipient you text or call will not know who you are (unless you tell them), however you are never completely anonymous when texting or making calls. If you break these terms, your device will be banned and your identity might be revealed to the authorities upon request. You must be at least 13 years old to use the service. Not for 911 emergency services. Have questions, problems, or feedback? Contact us at contact@flexiblenumbers.com

About

SkyDuo

Connect with friends and family globally through free video calls and messaging. This app also provides secondary phone numbers for private calling and texting, offering a secure and cost-effective communication solution.

Highlights
  • Free video calls across devices
  • Private second phone numbers
  • Cheap international calls and texts
  • Fun messaging with stickers and GIFs
  • End-to-end encrypted calls and messages
  • Low data usage for calls
Features
Read full description

SkyDuo is a FREE Video Chat and Messaging App + WiFi Phone App. Live face to face video chat with friends and family for free, even if they are in another country. Get multiple phone numbers for unlimited calling and texting, to any mobile or landline. It's cool and easy, private and secure, reliable and fun. • Free Video Calls across Any Device Work across mobile, tablet or any smart device. Just send an invite link to your friend, then start your free face time video chat. Samsung, LG, Huawei, Xiaomi, Vivo, Oppo, TCL, Micromax, Realme, Motorola, all supported. • Private Second Phone Numbers Tired of giving out your real phone number? Tired of carrying multiple phones with multiple SIM cards? Tired of expensive GSM contracts and bills? Download SIMless SkyDuo, say goodbye to old fashion. One App, Multiple Real US/CA/UK phone numbers for your choice. • Cheap or Free International Calls & Texts Beyond free online video chats, wifi phone call & text to any mobile/landline phone numbers in over 200 countries and regions are provided at super low rates. Earn your daily free credits, then enjoy free wifi phone calls, free sms/mms, free txt now. • Fun Messaging Fun communication should be without limits! Express yourself with customized emoticons, stickers, GIFs, doodles on duo face, play games together while duo video chat, send pictures, voices, videos or locations messages. Camera shy? Make voice calls to anyone, any number in the world. • Private and Secure All calls are end-to-end encrypted. And messages are encrypted in-line with international security standards (TLS). Third parties can never access your messages. And SkyDuo does not store your messages. They will be deleted as soon as they are received by the recipient. Delete your account, without leaving a trace. Enjoy your safe and secure SkyDuo chat. • Low Data Usage Save 40-90% of the vowifi and voip network traffic in real-time calls. Especially on cellular networks, saving your data money a lot. • Is SkyDuo Really FREE ? Yes. Free to make video calls and messages. FREE to get credits everyday. Check-in, watch videos to earn free credits, play games to win free credits, complete various reward tasks to get free credits like making calls or sending texts. All paid premium services could be redeemed by free credits. It's totally free as you use it more. • Amazing Premium Features Upgrade to SkyDuo Premium, enjoy all exclusive features including private numbers, ad-free, call recording, monthly free credits bonus, 2x free daily credits tasks, better price of out call/text, special ringtones and themes, etc. Download the app and enjoy your SkyDuo life right now! Much More Goodies: - Add 2nd, 3rd line to your phone/tablet, turn your devices into real dual mobile phone. Alter the number at any time. Switch a number, switch a life! Deliveries, business, posting online, sales people, business partners, shopping online, selling items on Craigslist, Etsy, Ebay, never embarrassed. Level your living a next plus! - Note: If Push notification is not enabled, you may not receive messages and calls. 911 is not supported. If any area rates are too high, contact us. We will work on it. And you might win a support reward! Subscriptions are for premium, which can be purchased in-app and be renewed weekly, monthly or yearly on your choice. Payment will be charged to your iTunes account. Subscription automatically renews within 24-hours prior to the end of the current period, unless auto-renew is turned off at least 24 hours before that. You may manage your subscriptions and turn off auto-renewal by going to your iTunes Account Settings. No cancellation of the current subscription is allowed during active subscription. See More in Terms and Privacy Policy https://www.phoneduo.app/terms.html, https://www.phoneduo.app/privacy.html. We are excited to hear your feedback on the app! Contact Us: support@phoneduo.app

Screenshots

Second Line Calling/Texting4 screens
SkyDuo4 screens

Verdict

The call

The clearest difference is rating: SkyDuo at 4.7 against Second Line Calling/Texting's 4.2. SkyDuo also leads on update cadence (every 11 days vs every 2 months) and review sentiment (78% vs 68%). On price, ratings volume, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Second Line Calling/Texting sells 8 in-app purchases, starting at $9.99 per month and SkyDuo sells 11 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

SkyDuo holds the better App Store score, 4.7 against 4.2. Both are backed by a comparable volume of ratings — 2.2K and 2K respectively. Written reviews point the same way: 68% of Second Line Calling/Texting's written reviews are positive against 78% of SkyDuo's.

UpkeepUpdate frequency

Second Line Calling/Texting ships an update every 2 months, SkyDuo every 11 days. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

Scorecard4 real differences · 6 level
Second Line Calling/Texting versus SkyDuo: the parameters behind the verdict, then further details
ParameterSecond Line Calling/TextingSkyDuo
PriceFreeFree
Rating4.2 (2.2K ratings)4.7 (2K ratings) — better
Positive reviews67.6% of reviews77.6% of reviews — better
Number of ratings2.2K — better2K
Update frequencyEvery 2 monthsEvery 11 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.612.0 — better
Further details — not scored
Size11 MB109 MB
Age rating4+12+
DeveloperBinaryPatternNingbo Juphoon System Software Co., Ltd.

Customer experience

Second Line Calling/Texting

All ratings2,047 ratings
Positive77.6%
Neutral8.1%
Negative14.3%
Written reviews111 reviews
Positive67.6%
Neutral6.3%
Negative26.1%

SkyDuo

All ratings1,981 ratings
Positive92.8%
Neutral3.3%
Negative3.9%
Written reviews107 reviews
Positive77.6%
Neutral4.7%
Negative17.8%

User reviews

Second Line Calling/Texting

From 2.2K App Store ratings

What we love

  • 👍 Easy and convenient
  • 🚀 Fast setup
  • 🔒 Flexible and secure
  • 💰 Good value for money
  • 📱 User-friendly interface

Room to improve

  • 🐛 Occasional technical issues
  • 🔍 Limited customer support
  • 💸 Expensive premium plans
  • 🔌 Unreliable call/text functionality

SkyDuo

From 2K App Store ratings

What we love

  • 👍 Good app for Apple to Android calling
  • 🚀 Duo has good quality video and allows drawing/doodling
  • 👍 Wonderful video chat app
  • 👍 Great video and sound quality
  • 👍 Highly recommended for communication with family/friends

Room to improve

  • 🐛 App does not work, phone number does not work, app closes
  • 🐛 App won't make any phone calls
  • 🐛 Misleading, need to have contacts registered before use
  • 🐛 Wrong app, not what was expected
  • 🔋 Audio quality could be improved

Bugs and requests

Second Line Calling/Texting

Reported bugs

4 issues
  • Dropped calls
  • Failed message deliveries
  • Disappearing contacts
  • Billing/subscription problems

Requested features

4 requests
  • Ability to send images/videos
  • More free credits/minutes
  • Improved customer support channels
  • Compatibility with newer OS versions

SkyDuo

Reported bugs

3 issues
  • App crashes, deletes itself, and doesn't work
  • Can't choose or change password
  • Payment issues, money deducted but no credit in app

Requested features

4 requests
  • Add group chat option
  • Allow texting with WiFi
  • Add more options like filters, screen sharing
  • Add ability to call two people on one call

In-app purchases

8 purchases

Second Line Calling/Texting

Subscriptions3
  • Premium Line$9.991 Month
  • Premium Number Plan3 Days trial$9.991 Month
  • Premium Number Plan Upgrade$9.991 Month
One-time5
  • 3 Coin Pack$2.99
  • 8 Coin Pack$5.99
  • 15 Coin Pack$9.99
Show 2 more
  • 25 Coin Pack$13.99
  • 60 Coin Pack$27.99
11 purchases

SkyDuo

Subscriptions8
  • Premium Lite Weekly$2.997 Days
  • US Number Plan Weekly$3.997 Days
  • 1 Line Unlimited Plan Monthly$4.991 Month
Show 5 more
  • US&CA Essential Plan Monthly$4.991 Month
  • US&CA Basic Plan Monthly$7.991 Month
  • US Number Plan Monthly$7.991 Month
  • Premium Monthly$9.991 Month
  • Premium Monthly1 Month trial$9.991 Month
One-time3
  • Dual Phone 10000 credits$1.99
  • Dual Phone 25000 credits$4.99
  • Dual Phone 50000 credits$9.99

Questions

Is Second Line Calling/Texting free?
Second Line Calling/Texting is free to download, with in-app purchases available.
Is SkyDuo free?
SkyDuo is free to download, with in-app purchases available.
Which has better reviews, Second Line Calling/Texting or SkyDuo?
SkyDuo is rated higher. Second Line Calling/Texting averages 4.2 out of 5 from 2.2K ratings, while SkyDuo averages 4.7 from 2K ratings.
Do Second Line Calling/Texting or SkyDuo have ads?
Neither Second Line Calling/Texting nor SkyDuo shows ads.
Which is updated more often, Second Line Calling/Texting or SkyDuo?
Second Line Calling/Texting ships an update every 2 months, and SkyDuo every 11 days. Most recently, Second Line Calling/Texting was updated on October 29, 2026 and SkyDuo on October 30, 2026.

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