Comparison

Callsling vs OneFill

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

Head to head
About

Callsling

This app allows users to send and receive calls and SMS messages over WiFi. It provides call tracking capabilities, linking incoming calls to their source like SEO or websites. The mobile application integrates with a cloud-based system for advanced lead generation and call handling.

Highlights
  • Send and receive calls via WiFi
  • Send and receive SMS via WiFi
  • Track calls from SEO and websites
  • Configure new call tracking numbers
  • Lead generation call tracking
  • Advanced call handling
Features
Read full description

Send and Receive Calls & SMS via WiFi. Track calls from SEO, Sites & more. Easy to use Mobile App which connects with the cloud-based application. You can configure a new call tracking number. Set up Lead Generation Call Tracking with advanced call handling.

About

OneFill

Features
Read full description

OneFill is the fast way for licensed insurance agents to complete carrier applications. Enter your client's information once, then auto-fill any carrier's web application with a single tap — no retyping the same name, address, and date of birth on every portal. Built for agents who work across multiple carriers, OneFill keeps each client's details in one organized record and fills the fields for you, so you spend less time on data entry and more time with clients. KEY FEATURES One client record, every carrier — enter info once, reuse it everywhere One-tap fill — populate a carrier application instantly Two-way capture — keep your client record updated as you work Instant eligibility — see results and move on quickly Built-in safeguards — bank and card numbers are never auto-filled; you always enter those manually on the carrier site Works as a Safari extension on the carrier pages you already use OneFill is a productivity tool for licensed professionals. It does not sell insurance, provide quotes, or submit applications on your behalf.

Screenshots

Callsling4 screens
OneFill1 screens

Verdict

The call

The clearest difference is update cadence: OneFill at every 8 days against Callsling's every 2 months. Callsling's advantage is iOS requirement (13.0 vs 17.6). On price, ads, in-app purchases and device support 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Callsling ships an update every 2 months, OneFill every 8 days. The most recent releases landed on October 2, 2026 and October 11, 2026 respectively.

Scorecard2 real differences · 8 level
Callsling versus OneFill: the parameters behind the verdict, then further details
ParameterCallslingOneFill
PriceFreeFree
Rating3.9 (7 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings7 — better—
Update frequencyEvery 2 monthsEvery 8 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationAd-supported—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better17.6
Further details — not scored
Size54 MB5 MB
Age rating4+4+
DeveloperDan KleinCassiel LLC

In-app purchases

None

Callsling

No in-app purchases

None

OneFill

No in-app purchases

Questions

Is Callsling free?
Callsling is free to download, with no in-app purchases.
Is OneFill free?
OneFill is free to download, with no in-app purchases.
Do Callsling or OneFill have ads?
Neither Callsling nor OneFill shows ads.
Which is updated more often, Callsling or OneFill?
Callsling ships an update every 2 months, and OneFill every 8 days. Most recently, Callsling was updated on October 2, 2026 and OneFill on October 11, 2026.

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